Should i go along with this and see if i can make peace with bff? Jump up and down and scream HELL NO!(?) Or just find an excuse to be elsewhere? Fridays lately we have typically reserved for "us", so i don't really want to give that up but... IDK, spending an evening with her and bff (and bff can actually be a very fun and engaging person) doesn't really excite me.
I find many elements of your sitch similar to mine. In 2012, my W had a much younger friend who was very toxic to the relationship. I think I made the mistake of letting this person be a part of our lives.
In your case, this sounds like you should think about your boundaries. Can you tell the W, "you BFF did this and this, and I will not spend time with her." ?